The Probert Encyclopaedia of General Information

DITCH

A ditch is a trench in the earth made by digging, particularly the term is used for a trench for draining wet land, or for making a fence to guard inclosures, or for preventing an enemy from approaching a town or fortress. In the latter sense it is called also a fosse or moat, and is dug round the rampart or wall between tho scarp and counterscarp.
Research Ditch